83 ideas
| 15010 | Your metaphysics is 'cheating' if your ontology won't support the beliefs you accept [Sider] |
| Full Idea: Ontological 'cheaters' are those ne'er-do-well metaphysicians (such as presentists, phenomenalists, or solipsists) who refuse to countenance a sufficiently robust conception of the fundamental to underwrite the truths they accept. | |
| From: Theodore Sider (Writing the Book of the World [2011], 08.4) | |
| A reaction: Presentists are placed in rather insalubrious company here, The notion of 'cheaters' is nice, and I associate it with Australian philosophy, and the reason that was admired by David Lewis. |
| 14977 | Metaphysics is not about what exists or is true or essential; it is about the structure of reality [Sider] |
| Full Idea: Metaphysics, at bottom, is about the fundamental structure of reality. Not about what's necessarily true. Not about what properties are essential. Not about conceptual analysis. Not about what there is. Structure. | |
| From: Theodore Sider (Writing the Book of the World [2011], 01) | |
| A reaction: The opening words of his book. I take them to be absolutely correct, and to articulate the new orthodoxy about metaphysics which has emerged since about 1995. He expands this as being about patterns, categories and joints. |
| 14994 | Extreme doubts about metaphysics also threaten to undermine the science of unobservables [Sider] |
| Full Idea: The most extreme critics of metaphysics base their critique on sweeping views about language (logical positivism), or knowledge (empiricism), ...but this notoriously threatens the science of unobservables as much as it threatens metaphysics. | |
| From: Theodore Sider (Writing the Book of the World [2011], 05.1) | |
| A reaction: These criticisms also threaten speculative physics (even about what is possibly observable). |
| 15003 | It seems unlikely that the way we speak will give insights into the universe [Sider] |
| Full Idea: It has always seemed odd that insight into the fundamental workings of the universe should be gained by reflection on how we think and speak. | |
| From: Theodore Sider (Writing the Book of the World [2011], 07.8) | |
| A reaction: A nice expression of what should by now be obvious to all philosophers - that analysis of language is not going to reveal very much. It is merely clearing the undergrowth so that we can go somewhere. |
| 14986 | Conceptual analysts trust particular intuitions much more than general ones [Sider] |
| Full Idea: Conceptual analysts generally regard intuitive judgements about particular cases as being far more diagnostic than intuitive judgements about general principles. | |
| From: Theodore Sider (Writing the Book of the World [2011], 02.4 n7) | |
| A reaction: Since I take the aim to be the building up an accurate picture about general truths, it would be daft to just leap to our intuitions about those general truths. Equally you can't cut intuition out of the picture (pace Ladyman). |
| 9641 | Definitions should be replaceable by primitives, and should not be creative [Brown,JR] |
| Full Idea: The standard requirement of definitions involves 'eliminability' (any defined terms must be replaceable by primitives) and 'non-creativity' (proofs of theorems should not depend on the definition). | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7) | |
| A reaction: [He cites Russell and Whitehead as a source for this view] This is the austere view of the mathematician or logician. But almost every abstract concept that we use was actually defined in a creative way. |
| 14981 | Philosophical concepts are rarely defined, and are not understood by means of definitions [Sider] |
| Full Idea: Philosophical concepts of interest are rarely reductively defined; still more rarely does our understanding of such concepts rest on definitions. ...(We generally understand concepts to the extent that we know what role they play in thinking). | |
| From: Theodore Sider (Writing the Book of the World [2011], 02.1) | |
| A reaction: I'm not sure that I agree with this. I suspect that Sider has the notion of definition in mind that is influenced by lexicography. Aristotle's concept of definition I take to be lengthy and expansive, and that is very relevant to philosophy. |
| 15015 | It seems possible for a correct definition to be factually incorrect, as in defining 'contact' [Sider] |
| Full Idea: Arguably, 'there is absolutely no space between two objects in contact' is false, but definitional of 'contact'. ...We need a word for true definitional sentences. I propose: 'analytic'. | |
| From: Theodore Sider (Writing the Book of the World [2011], 09.8) |
| 14992 | We don't care about plain truth, but truth in joint-carving terms [Sider] |
| Full Idea: What we care about is truth in joint-carving terms, not just truth. | |
| From: Theodore Sider (Writing the Book of the World [2011], 04.5) | |
| A reaction: The thought is that it matters what conceptual scheme is used to express the truth (the 'ideology'). Truths can be true but uninformative or unexplanatory. |
| 15012 | Orthodox truthmaker theories make entities fundamental, but that is poor for explanation [Sider] |
| Full Idea: According to the entrenched truthmaker theorist, the fundamental facts consist just of facts citing the existence of entities. It's hard to see how all the complexity we experience could possibly be explained from that sparse basis. | |
| From: Theodore Sider (Writing the Book of the World [2011], 08.5) | |
| A reaction: This may be the 'entrenched' truthmaker view, but it is not clear why there could not be more complicated fundamental truthmakers, with structure as well as entities. And powers. |
| 15023 | The Barcan schema implies if X might have fathered something, there is something X might have fathered [Sider] |
| Full Idea: If we accept the Barcan and converse Barcan schemas, this leads to surprising ontological consequences. Wittgenstein might have fathered something, so, by the Barcan schema, there is something that Wittgenstein might have fathered. | |
| From: Theodore Sider (Writing the Book of the World [2011], 11.9) | |
| A reaction: [He cites Tim Williamson for this line of thought] I was liking the Barcan picture, by now I am backing away fast. They cannot be serious! |
| 9634 | Set theory says that natural numbers are an actual infinity (to accommodate their powerset) [Brown,JR] |
| Full Idea: The set-theory account of infinity doesn't just say that we can keep on counting, but that the natural numbers are an actual infinite set. This is necessary to make sense of the powerset of ω, as the set of all its subsets, and thus even bigger. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5) | |
| A reaction: I don't personally find this to be sufficient reason to commit myself to the existence of actual infinities. In fact I have growing doubts about the whole role of set theory in philosophy of mathematics. Shows how much I know. |
| 9613 | Naïve set theory assumed that there is a set for every condition [Brown,JR] |
| Full Idea: In the early versions of set theory ('naïve' set theory), the axiom of comprehension assumed that for any condition there is a set of objects satisfying that condition (so P(x)↔x∈{x:P(x)}), but this led directly to Russell's Paradox. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: How rarely any philosophers state this problem clearly (as Brown does here). This is incredibly important for our understanding of how we classify the world. I'm tempted to just ignore Russell, and treat sets in a natural and sensible way. |
| 9615 | Nowadays conditions are only defined on existing sets [Brown,JR] |
| Full Idea: In current set theory Russell's Paradox is avoided by saying that a condition can only be defined on already existing sets. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: A response to Idea 9613. This leaves us with no account of how sets are created, so we have the modern notion that absolutely any grouping of daft things is a perfectly good set. The logicians seem to have hijacked common sense. |
| 9617 | The 'iterative' view says sets start with the empty set and build up [Brown,JR] |
| Full Idea: The modern 'iterative' concept of a set starts with the empty set φ (or unsetted individuals), then uses set-forming operations (characterized by the axioms) to build up ever more complex sets. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: The only sets in our system will be those we can construct, rather than anything accepted intuitively. It is more about building an elaborate machine that works than about giving a good model of reality. |
| 9642 | A flock of birds is not a set, because a set cannot go anywhere [Brown,JR] |
| Full Idea: Neither a flock of birds nor a pack of wolves is strictly a set, since a flock can fly south, and a pack can be on the prowl, whereas sets go nowhere and menace no one. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7) | |
| A reaction: To say that the pack menaced you would presumably be to commit the fallacy of composition. Doesn't the number 64 have properties which its set-theoretic elements (whatever we decide they are) will lack? |
| 15004 | 'Gunk' is an object in which proper parts all endlessly have further proper parts [Sider] |
| Full Idea: An object is 'gunky' if each of its parts has further proper parts; thus gunk involves infinite descent in the part-whole relation. | |
| From: Theodore Sider (Writing the Book of the World [2011], 07.11.2) |
| 14984 | Which should be primitive in mereology - part, or overlap? [Sider] |
| Full Idea: Should our fundamental theory of part and whole take 'part' or 'overlap' as primitive? | |
| From: Theodore Sider (Writing the Book of the World [2011], 02.3) |
| 14980 | There is a real issue over what is the 'correct' logic [Sider] |
| Full Idea: Certain debates over the 'correct' logic are genuine, and not linguistic or conceptual. | |
| From: Theodore Sider (Writing the Book of the World [2011], 01.3) | |
| A reaction: It is rather hard to give arguments in favour of this view, but I am pleased to have the authority of Sider with me. |
| 15000 | 'It is raining' and 'it is not raining' can't be legislated, so we can't legislate 'p or ¬p' [Sider] |
| Full Idea: I cannot legislate-true 'It is raining' and I cannot legislate true 'It is not raining', so if I cannot legislate either true then I cannot legislate-true the disjunction 'it is raining or it is not raining'. | |
| From: Theodore Sider (Writing the Book of the World [2011], 06.5) | |
| A reaction: This strikes me as a very simple and very persuasive argument against the idea that logic is a mere convention. I take disjunction to be an abstract summary of how the world works. Sider seems sympathetic. |
| 15020 | Classical logic is good for mathematics and science, but less good for natural language [Sider] |
| Full Idea: Despite its brilliant success in mathematics and fundamental science, classical logic applies uneasily to natural language. | |
| From: Theodore Sider (Writing the Book of the World [2011], 10.6) | |
| A reaction: He gives examples of the conditional, and debates over the meaning of 'and', 'or' and 'not', and also names and quantifiers. Many modern philosophical problems result from this conflict. |
| 15029 | Modal accounts of logical consequence are simple necessity, or essential use of logical words [Sider] |
| Full Idea: The simplest modal account is that logical consequence is just necessary consequence; another modal account says that logical consequences are modal consequences that involve only logical words essentially. | |
| From: Theodore Sider (Writing the Book of the World [2011], 12.3) | |
| A reaction: [He cites Quine's 'Carnap and Logical Truth' for the second idea] Sider is asserting that Humeans like him dislike modality, and hence need a nonmodal account of logical consequence. |
| 9605 | If a proposition is false, then its negation is true [Brown,JR] |
| Full Idea: The law of excluded middle says if a proposition is false, then its negation is true | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 1) | |
| A reaction: Surely that is the best statement of the law? How do you write that down? ¬(P)→¬P? No, because it is a semantic claim, not a syntactic claim, so a truth table captures it. Semantic claims are bigger than syntactic claims. |
| 15019 | Define logical constants by role in proofs, or as fixed in meaning, or as topic-neutral [Sider] |
| Full Idea: Some say that logical constants are those expressions that are defined by their proof-theoretic roles, others that they are the expressions whose semantic values are permutation-invariant, and still others that they are the topic-neutral expressions. | |
| From: Theodore Sider (Writing the Book of the World [2011], 10.3) | |
| A reaction: [He cites MacFarlane 2005 as giving a survey of this] |
| 15001 | 'Tonk' is supposed to follow the elimination and introduction rules, but it can't be so interpreted [Sider] |
| Full Idea: 'Tonk' is stipulated by Prior to stand for a meaning that obeys the elimination and introduction rules; but there simply is no such meaning; 'tonk' cannot be interpreted so as to obey the rules. | |
| From: Theodore Sider (Writing the Book of the World [2011], 06.5) | |
| A reaction: 'Tonk' thus seems to present a problem for so-called 'natural' deduction, if the natural deduction consists of nothing more than obey elimination and introduction rules. |
| 9649 | Axioms are either self-evident, or stipulations, or fallible attempts [Brown,JR] |
| Full Idea: The three views one could adopt concerning axioms are that they are self-evident truths, or that they are arbitrary stipulations, or that they are fallible attempts to describe how things are. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch.10) | |
| A reaction: Presumably modern platonists like the third version, with others choosing the second, and hardly anyone now having the confidence to embrace the first. |
| 9638 | Berry's Paradox finds a contradiction in the naming of huge numbers [Brown,JR] |
| Full Idea: Berry's Paradox refers to 'the least integer not namable in fewer than nineteen syllables' - a paradox because it has just been named in eighteen syllables. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5) | |
| A reaction: Apparently George Boolos used this quirky idea as a basis for a new and more streamlined proof of Gödel's Theorem. Don't tell me you don't find that impressive. |
| 9604 | Mathematics is the only place where we are sure we are right [Brown,JR] |
| Full Idea: Mathematics seems to be the one and only place where we humans can be absolutely sure that we got it right. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 1) | |
| A reaction: Apart from death and taxes, that is. Personally I am more certain of the keyboard I am typing on than I am of Pythagoras's Theorem, but the experts seem pretty confident about the number stuff. |
| 9622 | 'There are two apples' can be expressed logically, with no mention of numbers [Brown,JR] |
| Full Idea: 'There are two apples' can be recast as 'x is an apple and y is an apple, and x isn't y, and if z is an apple it is the same as x or y', which makes no appeal at all to mathematics. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4) | |
| A reaction: He cites this as the basis of Hartry Field's claim that science can be done without numbers. The logic is ∃x∃y∀z(Ax&Ay&(x¬=y)&(Az→z=x∨z=y)). |
| 9648 | π is a 'transcendental' number, because it is not the solution of an equation [Brown,JR] |
| Full Idea: The number π is not only irrational, but it is also (unlike √2) a 'transcendental' number, because it is not the solution of an algebraic equation. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch.10) | |
| A reaction: So is that a superficial property, or a profound one? Answers on a post card. |
| 9621 | Mathematics represents the world through structurally similar models. [Brown,JR] |
| Full Idea: Mathematics hooks onto the world by providing representations in the form of structurally similar models. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4) | |
| A reaction: This is Brown's conclusion. It needs notions of mapping, one-to-one correspondence, and similarity. I like the idea of a 'model', as used in both logic and mathematics, and children's hobbies. The mind is a model-making machine. |
| 9646 | There is no limit to how many ways something can be proved in mathematics [Brown,JR] |
| Full Idea: I'm tempted to say that mathematics is so rich that there are indefinitely many ways to prove anything - verbal/symbolic derivations and pictures are just two. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 9) | |
| A reaction: Brown has been defending pictures as a form of proof. I wonder how long his list would be, if we challenged him to give more details? Some people have very low standards of proof. |
| 9647 | Computers played an essential role in proving the four-colour theorem of maps [Brown,JR] |
| Full Idea: The celebrity of the famous proof in 1976 of the four-colour theorem of maps is that a computer played an essential role in the proof. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch.10) | |
| A reaction: The problem concerns the reliability of the computers, but then all the people who check a traditional proof might also be unreliable. Quis custodet custodies? |
| 9643 | Set theory may represent all of mathematics, without actually being mathematics [Brown,JR] |
| Full Idea: Maybe all of mathematics can be represented in set theory, but we should not think that mathematics is set theory. Functions can be represented as order pairs, but perhaps that is not what functions really are. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7) | |
| A reaction: This seems to me to be the correct view of the situation. If 2 is represented as {φ,{φ}}, why is that asymmetrical? The first digit seems to be the senior and original partner, but how could the digits of 2 differ from one another? |
| 9644 | When graphs are defined set-theoretically, that won't cover unlabelled graphs [Brown,JR] |
| Full Idea: The basic definition of a graph can be given in set-theoretic terms,...but then what could an unlabelled graph be? | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 7) | |
| A reaction: An unlabelled graph will at least need a verbal description for it to have any significance at all. My daily mood-swings look like this.... |
| 9625 | To see a structure in something, we must already have the idea of the structure [Brown,JR] |
| Full Idea: Epistemology is a big worry for structuralists. ..To conjecture that something has a particular structure, we must already have conceived of the idea of the structure itself; we cannot be discovering structures by conjecturing them. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4) | |
| A reaction: This has to be a crucial area of discussion. Do we have our heads full of abstract structures before we look out of the window? Externalism about the mind is important here; mind and world are not utterly distinct things. |
| 9628 | Sets seem basic to mathematics, but they don't suit structuralism [Brown,JR] |
| Full Idea: Set theory is at the very heart of mathematics; it may even be all there is to mathematics. The notion of set, however, seems quite contrary to the spirit of structuralism. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4) | |
| A reaction: So much the worse for sets, I say. You can, for example, define ordinality in terms of sets, but that is no good if ordinality is basic to the nature of numbers, rather than a later addition. |
| 9606 | The irrationality of root-2 was achieved by intellect, not experience [Brown,JR] |
| Full Idea: We could not discover irrational numbers by physical measurement. The discovery of the irrationality of the square root of two was an intellectual achievement, not at all connected to sense experience. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 1) | |
| A reaction: Brown declares himself a platonist, and this is clearly a key argument for him, and rather a good one. Hm. I'll get back to you on this one... |
| 9612 | There is an infinity of mathematical objects, so they can't be physical [Brown,JR] |
| Full Idea: A simple argument makes it clear that all mathematical arguments are abstract: there are infinitely many numbers, but only a finite number of physical entities, so most mathematical objects are non-physical. The best assumption is that they all are. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: This, it seems to me, is where constructivists score well (cf. Idea 9608). I don't have an infinity of bricks to build an infinity of houses, but I can imagine that the bricks just keep coming if I need them. Imagination is what is unbounded. |
| 9610 | Numbers are not abstracted from particulars, because each number is a particular [Brown,JR] |
| Full Idea: Numbers are not 'abstract' (in the old sense, of universals abstracted from particulars), since each of the integers is a unique individual, a particular, not a universal. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: An interesting observation which I have not seen directly stated before. Compare Idea 645. I suspect that numbers should be thought of as higher-order abstractions, which don't behave like normal universals (i.e. they're not distributed). |
| 9620 | Empiricists base numbers on objects, Platonists base them on properties [Brown,JR] |
| Full Idea: Perhaps, instead of objects, numbers are associated with properties of objects. Basing them on objects is strongly empiricist and uses first-order logic, whereas the latter view is somewhat Platonistic, and uses second-order logic. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 4) | |
| A reaction: I don't seem to have a view on this. You can count tomatoes, or you can count red objects, or even 'instances of red'. Numbers refer to whatever can be individuated. No individuation, no arithmetic. (It's also Hume v Armstrong on laws on nature). |
| 9639 | Does some mathematics depend entirely on notation? [Brown,JR] |
| Full Idea: Are there mathematical properties which can only be discovered using a particular notation? | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 6) | |
| A reaction: If so, this would seem to be a serious difficulty for platonists. Brown has just been exploring the mathematical theory of knots. |
| 9629 | For nomalists there are no numbers, only numerals [Brown,JR] |
| Full Idea: For the instinctive nominalist in mathematics, there are no numbers, only numerals. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5) | |
| A reaction: Maybe. A numeral is a specific sign, sometimes in a specific natural language, so this seems to miss the fact that cardinality etc are features of reality, not just conventions. |
| 9630 | The most brilliant formalist was Hilbert [Brown,JR] |
| Full Idea: In mathematics, the most brilliant formalist of all was Hilbert | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5) | |
| A reaction: He seems to have developed his fully formalist views later in his career. See Mathematics|Basis of Mathematic|Formalism in our thematic section. Kreisel denies that Hilbert was a true formalist. |
| 9608 | There are no constructions for many highly desirable results in mathematics [Brown,JR] |
| Full Idea: Constuctivists link truth with constructive proof, but necessarily lack constructions for many highly desirable results of classical mathematics, making their account of mathematical truth rather implausible. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: The tricky word here is 'desirable', which is an odd criterion for mathematical truth. Nevertheless this sounds like a good objection. How flexible might the concept of a 'construction' be? |
| 9645 | Constructivists say p has no value, if the value depends on Goldbach's Conjecture [Brown,JR] |
| Full Idea: If we define p as '3 if Goldbach's Conjecture is true' and '5 if Goldbach's Conjecture is false', it seems that p must be a prime number, but, amazingly, constructivists would not accept this without a proof of Goldbach's Conjecture. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 8) | |
| A reaction: A very similar argument structure to Schrödinger's Cat. This seems (as Brown implies) to be a devastating knock-down argument, but I'll keep an open mind for now. |
| 15017 | Supervenience is a modal connection [Sider] |
| Full Idea: Supervenience is just a kind of modal connection. | |
| From: Theodore Sider (Writing the Book of the World [2011], 09.10) | |
| A reaction: It says what would happen, as well as what does. This is big for Sider because he rejects modality as a feature of actuality. I think the world is crammed full of modal facts, so supervenience should be a handy tool for me. |
| 15008 | Is fundamentality in whole propositions (and holistic), or in concepts (and atomic)? [Sider] |
| Full Idea: The locus of fundamentality for a Finean is the whole proposition, whereas for me it is the proposition-part. Fundamentality is holistic for the Finean, atomistic for me. | |
| From: Theodore Sider (Writing the Book of the World [2011], 08.3) | |
| A reaction: This is because Kit Fine has pushed fundamentality into a relation (grounding), rather than into the particular entities involved (if I understand Sider's reading of him aright). My first intuition is to side with Sider. I'm on Sider's side... |
| 15013 | Tables and chairs have fundamental existence, but not fundamental natures [Sider] |
| Full Idea: The existence of tables and chairs is just as fundamental as the existence of electrons (in contrast, perhaps, with smirks and shadows, which do not exist fundamentally). However, tables and chairs have nonfundamental natures. | |
| From: Theodore Sider (Writing the Book of the World [2011], 08.7) | |
| A reaction: This seems to be a good clarification, and to me the 'nature' of something points towards its essence. However, I suppose he refers here to the place of something in a dependence hierarchy. But then, why does it have that place? What power? |
| 9619 | David's 'Napoleon' is about something concrete and something abstract [Brown,JR] |
| Full Idea: David's painting of Napoleon (on a white horse) is a 'picture' of Napoleon, and a 'symbol' of leadership, courage, adventure. It manages to be about something concrete and something abstract. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 3) | |
| A reaction: This strikes me as the germ of an extremely important idea - that abstraction is involved in our perception of the concrete, so that they are not two entirely separate realms. Seeing 'as' involves abstraction. |
| 15014 | Unlike things, stuff obeys unrestricted composition and mereological essentialism [Sider] |
| Full Idea: Stuff obeys unrestricted composition and mereological essentialism, whereas things do not. | |
| From: Theodore Sider (Writing the Book of the World [2011], 09.6.2) | |
| A reaction: [He cites Markosian 2004] |
| 15009 | We must distinguish 'concrete' from 'abstract' and necessary states of affairs. [Sider] |
| Full Idea: The truthmaker theorist's 'concrete' states of affairs must be distinguished from necessarily existing 'abstract' states of affairs. | |
| From: Theodore Sider (Writing the Book of the World [2011], 08.4) | |
| A reaction: [He cites Plantinga's 'Nature of Necessity' for the second one; I presume the first one is Armstrong] |
| 14983 | Accept the ontology of your best theory - and also that it carves nature at the joints [Sider] |
| Full Idea: We can add to the Quinean advice to believe the ontology of your best theory that you should also regard the ideology of your best theory as carving at the joints. | |
| From: Theodore Sider (Writing the Book of the World [2011], 02.3) | |
| A reaction: I've never liked the original Quinean formulation, but this is much better. I just take my ontological commitments to reside in me, not in whatever theory I am currently employing. I may be dubious about my own theory. |
| 14978 | A property is intrinsic if an object alone in the world can instantiate it [Sider] |
| Full Idea: Chisholm and Kim proposed a modal notion of an 'intrinsic' property - that a property is intrinsic if and only if it is possibly instantiated by an object that is alone in the world. | |
| From: Theodore Sider (Writing the Book of the World [2011], 01.2) | |
| A reaction: [He cites Chisholm 1976:127 and Kim 1982:59-60] Sider then gives a counterexample from David Lewis (Idea 14979). |
| 14995 | Predicates can be 'sparse' if there is a universal, or if there is a natural property or relation [Sider] |
| Full Idea: For Armstrong a predicate is sparse when there exists a corresponding universal; for Lewis, a predicate is sparse when there exists a corresponding natural property or relation. | |
| From: Theodore Sider (Writing the Book of the World [2011], 06) | |
| A reaction: I like 'sparse' properties, but have no sympathy with Armstrong, and am cautious about Lewis. I like Shoemaker's account, which makes properties even sparser. 'Abundant' so-called properties are my pet hate. They are 'predicates'! |
| 15026 | Essence (even if nonmodal) is not fundamental in metaphysics [Sider] |
| Full Idea: We should not regard nonmodal essence as being metaphysically basic: fundamental theories need essence no more than they need modality. | |
| From: Theodore Sider (Writing the Book of the World [2011], 12.1) | |
| A reaction: He is discussing Kit Fine, and notes that Fine offers a nonmodal view of essence, but still doesn't make it fundamental. I am a fan of essences, but making them fundamental in metaphysics seems unlikely. |
| 15030 | Humeans say that we decide what is necessary [Sider] |
| Full Idea: The spirit of Humeanism is that necessity is not a realm to be discovered. We draw the lines around what is necessary. | |
| From: Theodore Sider (Writing the Book of the World [2011], 12.3) | |
| A reaction: I disagree, but it is hard to argue the point. My intuitions are that the obvious necessities of logic and mathematics reflect the way nature has to be. The deepest necessities are patterns (about which God has no choice). |
| 15031 | Modal terms in English are entirely contextual, with no modality outside the language [Sider] |
| Full Idea: English modals are context-dependent through and through; there is no stable 'outer modality'. | |
| From: Theodore Sider (Writing the Book of the World [2011], 12.7) | |
| A reaction: Sider has been doing so well up to here. To me this is swallowing the bait of linguistic approaches to philosophy which he has fought so hard to avoid. |
| 15027 | If truths are necessary 'by convention', that seems to make them contingent [Sider] |
| Full Idea: If □φ says that φ is true by convention, then □φ would apparently turn out to be contingent, since statements about what conventions we adopt are not themselves true by convention. The main axioms of S4 and S5 would be false. | |
| From: Theodore Sider (Writing the Book of the World [2011], 12.1) |
| 15028 | Conventionalism doesn't seem to apply to examples of the necessary a posteriori [Sider] |
| Full Idea: Conventionalism is apparently inapplicable to Kripke's and Putnam's examples of the necessary a posteriori (and, relatedly, to de re modality). | |
| From: Theodore Sider (Writing the Book of the World [2011], 12.1) | |
| A reaction: [Sidelle 1989 discusses this] |
| 15033 | Humeans says mathematics and logic are necessary because that is how our concept of necessity works [Sider] |
| Full Idea: Why are logical (or mathematical, or analytic...) truths necessary? The Humean's answer is that this is just how our concept of necessity works. | |
| From: Theodore Sider (Writing the Book of the World [2011], 12.11) | |
| A reaction: This is why I (unlike Sider) am not a Humean. If we agreed that 'necessary' meant 'whatever is decreed by the Pope', that would so obviously not be necessary that we would have to start searching nature for true necessities. |
| 15025 | The world does not contain necessity and possibility - merely how things are [Sider] |
| Full Idea: At bottom, the world is an amodal place. Necessity and possibility do not carve at the joints; ultimate reality is not 'full of threats and promises' (Goodman). The book of the world says how things are, not how they must or might be. | |
| From: Theodore Sider (Writing the Book of the World [2011], 12) | |
| A reaction: Nice to see this expressed so clearly. I find it much easier to disagree with as a result. At first blush I would say that if you haven't noticed that the world is full of threats and promises, you should wake up and smell the coffee. Actuality is active. |
| 14988 | A theory which doesn't fit nature is unexplanatory, even if it is true [Sider] |
| Full Idea: 'Theories' based on bizarre, non-joint-carving classifications are unexplanatory even when true. | |
| From: Theodore Sider (Writing the Book of the World [2011], 03.1) | |
| A reaction: This nicely pinpoints why I take explanation to be central to whole metaphysical enterprise. |
| 14982 | If I used Ramsey sentences to eliminate fundamentality from my theory, that would be a real loss [Sider] |
| Full Idea: If the entire theory of this book were replaced by its Ramsey sentence, omitting all mention of fundamentality, something would seem to be lost. | |
| From: Theodore Sider (Writing the Book of the World [2011], 02.2 n2) | |
| A reaction: It is a moot point whether Ramsey sentences actually eliminate anything from the ontology, but trying to wriggle out of ontological commitment looks a rather sad route to follow. |
| 14989 | Problem predicates in induction don't reflect the structure of nature [Sider] |
| Full Idea: 'Is nonblack', 'is a nonraven', and 'grue' fail to carve at the joints. | |
| From: Theodore Sider (Writing the Book of the World [2011], 03.3) | |
| A reaction: A lot more than this needs to said, but this remark encapsulates why I find most of these paradoxes of induction uninteresting. They are all the creations of logicians, rather than of scientists. |
| 14997 | Two applications of 'grue' do not guarantee a similarity between two things [Sider] |
| Full Idea: The applicability of 'grue' to each of a pair of particulars does not guarantee the similarity of those particulars. | |
| From: Theodore Sider (Writing the Book of the World [2011], 06.2) | |
| A reaction: Grue is not a colour but a behaviour. If two things are 'mercurial' or 'erratic', will that ensure a similarity at any given moment? |
| 14990 | Bayes produces weird results if the prior probabilities are bizarre [Sider] |
| Full Idea: In the Bayesian approach, bizarre prior probability distributions will result in bizarre responses to evidence. | |
| From: Theodore Sider (Writing the Book of the World [2011], 03.3) | |
| A reaction: This is exactly what you find when people with weird beliefs encounter ridiculous evidence for things. It doesn't invalidate the formula, but just says rubbish in rubbish out. |
| 15005 | Explanations must cite generalisations [Sider] |
| Full Idea: Explanations must cite generalisations. | |
| From: Theodore Sider (Writing the Book of the World [2011], 07.13) | |
| A reaction: I'm uneasy about this. Presumably some events have a unique explanation - a unique mechanism, perhaps. Language is inescapably general in its nature - which I take to be Aristotle's reason for agreeing the Sider. [Sider adds mechanisms on p.159] |
| 15011 | If the ultimate explanation is a list of entities, no laws, patterns or mechanisms can be cited [Sider] |
| Full Idea: Ultimate explanations always terminate in the citation of entities; but since a mere list of entities is so unstructured, these 'explanations' cannot be systematized with detailed general laws, patterns, or mechanisms. | |
| From: Theodore Sider (Writing the Book of the World [2011], 08.5) | |
| A reaction: We just need to distinguish between ultimate ontology and ultimate explanations. I think explanations peter out at the point where we descend below the mechanisms. Patterns or laws don't explain on their own. Causal mechanisms are the thing. |
| 15018 | Intentionality is too superficial to appear in the catalogue of ultimate physics [Sider] |
| Full Idea: One day the physicists will complete the catalogue of ultimate and irreducible properties of things. When they do, the like of spin, charm and charge will perhaps appear on the list. But aboutness sure won't; intentionality simply doesn't go that deep. | |
| From: Theodore Sider (Writing the Book of the World [2011], 4 Intro) | |
| A reaction: Fodor's project is to give a reductive, and perhaps eliminative, account of intentionality of mind, while leaving open what one might do with the phenomenological aspects. Personally I don't think they will appear on the list either. |
| 9611 | 'Abstract' nowadays means outside space and time, not concrete, not physical [Brown,JR] |
| Full Idea: The current usage of 'abstract' simply means outside space and time, not concrete, not physical. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: This is in contrast to Idea 9609 (the older notion of being abstracted). It seems odd that our ancestors had a theory about where such ideas came from, but modern thinkers have no theory at all. Blame Frege for that. |
| 9609 | The older sense of 'abstract' is where 'redness' or 'group' is abstracted from particulars [Brown,JR] |
| Full Idea: The older sense of 'abstract' applies to universals, where a universal like 'redness' is abstracted from red particulars; it is the one associated with the many. In mathematics, the notion of 'group' or 'vector space' perhaps fits this pattern. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 2) | |
| A reaction: I am currently investigating whether this 'older' concept is in fact dead. It seems to me that it is needed, as part of cognitive science, and as the crucial link between a materialist metaphysic and the world of ideas. |
| 14999 | Prior to conventions, not all green things were green? [Sider] |
| Full Idea: It is absurd to say that 'before we introduced our conventions, not all green things were green'. | |
| From: Theodore Sider (Writing the Book of the World [2011], 06.5) | |
| A reaction: Well… Different cultures label the colours of the rainbow differently, and many of them omit orange. I suspect the blue/green borderline has shifted. |
| 9640 | A term can have not only a sense and a reference, but also a 'computational role' [Brown,JR] |
| Full Idea: In addition to the sense and reference of term, there is the 'computational' role. The name '2' has a sense (successor of 1) and a reference (the number 2). But the word 'two' has little computational power, Roman 'II' is better, and '2' is a marvel. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 6) | |
| A reaction: Very interesting, and the point might transfer to natural languages. Synonymous terms carry with them not just different expressive powers, but the capacity to play different roles (e.g. slang and formal terms, gob and mouth). |
| 14998 | Conventions are contingent and analytic truths are necessary, so that isn't their explanation [Sider] |
| Full Idea: To suggest that analytic truths make statements about linguistic conventions is a nonstarter; statements about linguistic conventions are contingent, whereas the statements made by typical analytic sentences are necessary. | |
| From: Theodore Sider (Writing the Book of the World [2011], 06.5) | |
| A reaction: That 'anything yellow is extended' is not just a convention should be fairly obvious, and it is obviously necessary. But we can say that bachelors are necessarily unmarried men - given the current convention. |
| 15016 | Analyticity has lost its traditional role, which relied on truth by convention [Sider] |
| Full Idea: Nothing can fully play the role traditionally associated with analyticity, for much of that traditional role presupposed the doctrine of truth by convention. | |
| From: Theodore Sider (Writing the Book of the World [2011], 09.8) | |
| A reaction: Sider rejects Quine's attack on analyticity, but accepts his critique of truth by convention. |
| 6004 | The cardinal virtues are theoretical (based on knowledge), and others are 'non-theoretical' [Hecato, by Dorandi] |
| Full Idea: Hecato defined the cardinal virtues as 'theoretical', that is, based on knowledge, and to these he opposed those that are 'non-theoretical', for example, health, beauty, strength of spirit, and courage. | |
| From: report of Hecato (fragments/reports [c.70 BCE]) by Tiziano Dorandi - Hecato of Rhodes | |
| A reaction: Mostly these are Aristotle's external and non-external virtues, except that courage is here included among the former, implying, presumably, that it is more of a natural gift than an intellectual achievement. |
| 9635 | Given atomism at one end, and a finite universe at the other, there are no physical infinities [Brown,JR] |
| Full Idea: There seem to be no actual infinites in the physical realm. Given the correctness of atomism, there are no infinitely small things, no infinite divisibility. And General Relativity says that the universe is only finitely large. | |
| From: James Robert Brown (Philosophy of Mathematics [1999], Ch. 5) | |
| A reaction: If time was infinite, you could travel round in a circle forever. An atom has size, so it has a left, middle and right to it. Etc. They seem to be physical, so we will count those too. |
| 14985 | The notion of law doesn't seem to enhance physical theories [Sider] |
| Full Idea: Adding the notion of law to physical theory doesn't seem to enhance its explanatory power. | |
| From: Theodore Sider (Writing the Book of the World [2011], 02.4) | |
| A reaction: I agree with his scepticism about laws, although Sider offers it as part of his scepticism about modal facts being included in explanations of actuality. Personally I like dispositions, but not laws. See the ideas of Stephen Mumford. |
| 14987 | Many of the key theories of modern physics do not appear to be 'laws' [Sider] |
| Full Idea: That spacetime is 4D Lorentzian manifold, that the universe began with a singularity, and in a state of low entropy, are all central to physics, but it is a stretch to call them 'laws'. ...It has been argued that there are no laws of biology. | |
| From: Theodore Sider (Writing the Book of the World [2011], 03.1) |
| 14991 | Space has real betweenness and congruence structure (though it is not the Euclidean concepts) [Sider] |
| Full Idea: In metaphysics, space is intrinsically structured; the genuine betweenness and congruence relations are privileged in a way that Euclidean-betweenness and Euclidean-congruence are not. | |
| From: Theodore Sider (Writing the Book of the World [2011], 03.4) | |
| A reaction: I note that Einstein requires space to be 'curved', which implies that it is a substance with properties. |
| 15021 | The central question in the philosophy of time is: How alike are time and space? [Sider] |
| Full Idea: The central question in the philosophy of time is: How alike are time and space? | |
| From: Theodore Sider (Writing the Book of the World [2011], 11.1) |
| 15024 | The spotlight theorists accepts eternal time, but with a spotlight of the present moving across it [Sider] |
| Full Idea: The spotlight theorist accepts the block universe, but also something in addition: a joint-carving monadic property of presentness, which is possessed by just one moment of time, and which 'moves', to be possessed by later and later times. | |
| From: Theodore Sider (Writing the Book of the World [2011], 11.9) | |
| A reaction: This seems better than the merely detached eternalist view, which seems to ignore the key phenomenon. I just can't comprehend any theory which makes the future as real as the past. |